The present invention relates to a wireless communication technology, more specifically to a technology which may be effectively applied, while increase of power consumption is controlled, for improving linearity of a semiconductor integrated circuit device comprising an amplifying circuit to amplify the code division multiplexed transmitting signal. Moreover, the present invention relates to a technology which may be effectively applied to a semiconductor integrated circuit device for communication constituting a wireless communication device, for example, of W-CDMA (Wideband Code Division Multiple Access) system and to a wireless communication device such as a mobile telephone or the like comprising the same semiconductor integrated circuit device.
In the wireless communication device such as a mobile telephone (mobile communication device), a multiplex system is employed to increase the amount of data to be transmitted. The present multiplex system used for the mobile telephone includes a TDMA system (time division multiplex system) and a CDMA system (code division multiplex system) or the like. The CDMA system is a communication system where a plurality of diffused codes having orthogonality in the same frequency space are used for spectrum diffusion of carrier and the diffused carriers are assigned to a plurality of channels. The CDMA system is employed for the mobile telephone of the W-CDMA system. In the mobile telephone of the PDC (Personal Digital Cellular) system and GSM (Global System for Mobile Communication) system, the TDMA system is employed.
In the mobile telephone of W-CDMA system, the I, Q signals generated based on the transmission data in a baseband circuit are supplied to a transmitting circuit including a modulation circuit, the signals obtained by modulating a local oscillation signal with the I, Q signals are supplied to a power amplifier for the power amplification and finally the amplified signals are outputted from an antenna. For the mobile telephone of the W-CDMA system, there is provided a system where level and accuracy of an average output power corresponding to the output request level transmitted from a base station are determined by the specification, gain of a power amplifier is controlled with an output control signal supplied from the baseband circuit, and signals are transmitted in the specified output power.